Stoker-operating system



Feb. 7, 1928. 1,658,049 c. l., HowsE STOKER OPERATING SYSTEM Filed March2, 1922 s sheets-sheet 1 Feb. 7, 1928. 1,658,049

c. L. HowsE v STOKER OPERATING SYSTEM- Filed March 2, 1922 3Sheets-Sheet 3 itl PATE

CURTIS L. HOWSE, F DETROIT, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, TORILEY STOKER CORPORATION, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF:MASSACHUSETTS STOKER-OPERATING SYSTEM.

Application led March 2, 1922. Serial No. 540,648.

My invention relates to the hydraulic operation of stolierfra-m engines,and provides a system that is simple in its parts, flexible in itscapability for taking care of widely varying sizes of plants and forconvenient placement of its mechanical elements, economical ininstallation and operation, and positive and efficient in itsfunctioning. For the attainment of these and other objects 'which willbecome apparentto those skilled in the art from the followingdescription, my invention consists in the combinations and arrangementsand constructions of parts hereinafter described and claimed.

1n the drawings l have illustrated an embodiment of my invention,chiefly by' diagrammatic illustration without attempted illustration ofexact proportions and locations of part-s which will be varied to suitthe needs of the particular plants.

ln such drawings, Fig. 1 is a diagrammatic perspective typifying aconvenient installation as to the principal elements; Fig. 2 is avertical section through a controlling valve; Fig. 3 illustrates anengine-valve with parts broken away; Fig. Llis a similar view showingthe valve in a diEerent position. Figs. 5 and 6 are front and side ele`rations of a modified engine valve organization.

'lhe furnace 10 may be equipped with any suitable automatic Stoker towhich fuel is supplied from hopper 11 by the usual ram mechanisms 12,equal in number to the number of retorts employed, each such ram beingdriven by an engine 13. Air to support combustion may be supplied by afan 14 which preferably is driven at a speed suitable to the demandevidenced by steam pressure in boiler 16, fan speed increasing as boilerpressure drops, and decreasing as boiler pressure rises. As one means tothis end the fan shaft 17 is shown as driven by an engine 18 operated atvarying speeds consistent with the boiler demand as aforesaid by theinterposition of a pressure regulator of any suitable automatic typeindi cated at 19, in the supply connection 20 of said engine with theboiler.

For hydraulically operating the ram engines 13, l provide a pump 21suitably driven, as by electric motor 22, to take liquid,

preferably oil, from the sump or supply tank 23 and deliver it throughpipe 24 to a supply header 25 for the engines,return `connections beingmade by `return header 26 to pipe 27 running back to the sump 23. Forstabilizing the pressure conditions in the supply pipe 24 a pressuretank 28 may be connected thereto and, if desired, the pumpmotor 22 mayhave its circuit controlled by a pressure gauge 27 on the tank as oneavailable means ofinsuring against the development of excessivepressure.

Normally full operating pressure exists in pressure' header 25, but thispressure may effectively be made to be impulsive rather than steady bythe provision of a pressureinterrupting valve 30, connected to the unionof the pipes 24 and 25 and having a rc lief connection 31 to the returnpipe 27. As shown in Fig. 2 this valve may in princple be asimple liftvalve with its valving element 32 normally closing communication betweenthe pressure port 24" which is connected to pipe 24 and the relief port31 which is connected to pipe 31. The valve is lifted by a cam 33 onshaft 34, and in order that the impulse-frequency shall vary in acscordance with the demand for maintenance of boiler pressure (suchfrequency increasing as boiler pressure drops and decreasing as boilerpressure rises) the shaft 34 is preferably driven by a suitableconnection'with fan shaft 17, such as connecting belt and suitablepulleys on said shafts.

Thus, periodically, the lifting of valve 32 opens communication betweenpipe 24 (and the pressure tank 28) and the return pipes 31 and 27, sorelieving header 25 from pressure during such time as the valve is open,and the periodicity of this reduction of pressure in header 25 willdepend upon the pressure conditions in the boiler, governing the speedof operation of the fan. Thus pipe 25 is subjected to impulsivepressure, the frequency of pressure relief being automatically varied.

In connection with each engine 13 I provide an automatic,pressure-impulse controlled valve` normally establishing connectionbetween one end of the engine and the pressure header 25 and between theother end of the engine and the return header 26,

but operatable periodically, after occurrence of a predetermmed numberof impulses, automatically to reverse these connections; provision beingmade for selective setting of the number of impulses prerequisite tosuch reversing actien of the valve.

In the drawings I have shown two forms of valve mechanisms, thatillustrated in Figs. 1, 3 and 4 utilizing the valving element itself foractuation of the selectively settable reversal-controlling mechanism,and that illustrated in Five. 5 and-6 showing a rotary valve providedwith extraneous impulsetranslating mechanism.

In the construction shown in Figs. 1, 3 and 4 a vertical valve casing 40is provided, prefera'bly adjacent the respective engmes, providing atdifferent elevations or vertical stages a central port-41 communicatingwith the branch pressure-pi pe 25 for that engine; near its top andbottom with respective ports 42, 42 both connected with the branch 26 ofthe return pipe 26; and intermediate the stated three ports respectiveupper and lower ports 43 and 43 connected by pipes 44 and 44 withopgiosite ends of the cylinder of engine 13. pecically the' upper andlower ports 43, 43 are shown as connected respectively with the ram-endand the head-end of the engine. The valve casing 40 is made with abore'of two diameters for respective cooperation with the larger andsmaller' heads 45 and/45 of a valving element 46 the stem 47 of whichextends through the top of the casing. Normally the larger head 45stands interposed between pressure port 41 and engine port 43, whilesmaller head 45 is interposed between engine port 43 and relief port42', but the space between the valve heads under these conditionsestablishes communication between pressure port41 and engine port 43.Owing to the unbalanced pressure-receptive surfaces of the valve, eachpressure impulse communicated through pipe 25 tends to raise the valveto the position shown in dotted lines in Fig.

4, where it will establish connection between ports 41 and 43; cut offconnection between ports 42 and 43; establish connection between ports43 and 42', and cut off connection between port 43 and port 41. Thevalve has, however, a limited range of permissive motion without varyingthe normal port-conditions first stated and will return to lowestposition when the pressure-impulseends.

Associated with the valve is selective mechanism, operated by the valvemovement for restraining the pressure-responsive motion of the valve toits closed range during that number of impulses for which the mechanismis set, and then releasing the valve for full movement toconnection-reversing position,

' such mechanism being self-restoring after 'the full movement has takenplace. A stopsector 50 pivoted at 51 stands normally in tcrposed 1n thepath `of reciprocation oi valve stem 47, but is movable' to position tofree the valve stem for full-stroke, by means of a ratchet sector 53,the pin 54 of which may carry the stop sector in clockwise direction.This r-atchet sector, when freed from stopped by theI sector 50, pawl 57 is caused to advance the ratchet sector a definite distance,preferablyone step. Should the stop sector 50 not be in the path of thevalve stem, the pin 60, passing the end of the cam surface 59, strikesthe tail 57 of pawl 57 and rocks the pawl out of engagement with theratchet tothe releasing or abnormal position shown in dotted lines inFig. 4. A iolding pawl 62, cooperating with the ratchet, is'sopositioned that this abnormal movement `of the feeding pawl 57 willcause it to strike the holding pawl and move it out ofratchet-engagement.

Now it will be apparent that in the operation of the system set forth,the pumpsupplies hydraulic pressure, steadied by the 'provision ofpressure tank 28, to the pipeline 24, and this is communicated direct toengine pressure-header 25 and to the branch pipes 25', except at thoseintervals when thel valve 30, operating with a periodicity determined byboiler-pressure conditions opens the "short-circuitingl connections frompipe 24 through pipe 31 directly into the return pipe 27, thus makingthe pressure in pipe 25 impulsive. Normally this impulsive pressureiscoinmunicated through ports 41 and 43 of the engine-valve to the headend of the engine, so holding the ram in innermost position. Eachimpulse moves the engine valve Within its closed range limited by theengagement or' valve stem 47 with the stop sector 50, onaccount of theunbalanced relation between the valve heads 45,45. Each such movement ofthe valve stem advances the ratchet mechanism until stop 50 is retractedfrom operative position, whereupon the valve makes a full stroke on ltsnext impulse-reception, moving to the position shown in dotted lines in-Fig. 4 andl communicating the pressure impulse, through connections 41and 43, to the ram end'of the engine, such pressure impulse serving todrive the ram on its out-stroke, and the liquid from the head end of theengine cylinder inding escape to the return pipe 27 through thecommunicating ports 43 and 42 of the valve and the return header 26.

In Figs. 5 and 6 I have illustrated another form of engine valve forserving a like purpose,in which an ordina-ry fourport rotary valve 7 0is employed, its plug 71 or valve-proper being movable from positionshown Where pipes 25 and 44 and 26 and 44 are connected to positionreversing the communication of the pressure and return pipes with theengine plpes 44, 44. The valve stem is provided with a ratchet Wheel 72self-returnable, when released from the holding paWl 73, by the actionof Weighty 74, the home position of Which is determined by a stop pin75. The ratchet is advanced from home position a certain number of stepsby the active pawl 7 G carried by the rod of piston 77 in cylinder 78which is connected as at 79 to an impulse-receiving pipe such as pipe25. The plunger 77 thus will be impulse-raised and may be returned byspring 80, thereby to actuate the ratchet wheel through a number ofstepsnormally determined by the adjustment of shield 81. which is rotarilysettable by means of pin S2. In order to insure that the valve Willalways pass through an arc sutiicient completely to sweep by a port asthe result of a single impulse, high teeth 8l may be pro-v vided onthe'ratchet to project beyond the shield 8l at an appropriate criticalpoint, so insuring that the ratchet Will receive a full movement on thecritical stroke of the reversing action, regardless of the setting ofshield 81. On this critical movement a pin 83 on the ratchetl moves areleasing arm 84 to trip out the holding paWl 7 8, freeing the ratchetfor return movement as soon as the live paWl 76 retracts. The releasingarm 84 stays in this position until carried back to normal position bythe pin 85 of the ratchet wheel substantially upon completion of thereturn movement of the ratchet.

Itwill thus be seen that in the broader aspects of my invention theconversion of impulse in the pressure pipe into movements ofa selectivedevice for determining the periodicity of reversal of the valve of theengine may be efected from a pressure-responsive part that either is aportion of the valve proper or is extraneous to the valveproper, and thedetails of construction, in this regard as in many others, may be Widelyvaried within the scope of the appended claims.

I claim: v

1. -In a Stoker-ram driving system, the combination with a ram and itsengine, of high-pressure//and return connections reversibly connectiblewith opposite ends of the engine, a source of hydraulic prep/sureassociated with said connections to supply the engine-operating 'powertherethrough,

automatic means for periodically interrupting the pressure-supplythrough said highpressure connection to create pressure-impulsestherein, and impulse-responsive and valving means operatively associatedwith said connection and acting in response to said pressure impulsestherein periodically to reverse said engine connections.

2. A structure as set forth in claim 1 wherein said automatic means forperiodically interrupting the pressure supply includes a valve forshort-circuiting the high pressure connection to the return connection.

3. The combination with a steam boiler, a stoker ram, and a ram-engine,of high pressure and return connections reversibly connectible with theopposite ends of said engine, a source of hydraulic pressure associatedwith said connections to supply the enlgine-operating powertherethrough, means for periodically interrupting the pressuresupplythrough said high-pressure connection to create pressure-impulsestherein, impulse-responsive and valving means operatively associatedwith said connection and acting in response to said pressure-impulsestherein to lreverse said engine-connections, and'means responsive tovariations of boiler pressure for operating said pressure-interruptingmeans With varying frequency.

4. In a Stoker-ram driving system, the combination with a. Stokerram.and its engine having a piston, of high-pressure and returnconnections for said engine, automatic means associated With saidconnections for creating periodic pressure-impulses in saidhigh-pressure connection, a valve movable to open said high pressureconnection to one end of the engine and the return connection to theother end thereof in one valve position and to .reversev theseconnections in another valve position, self-restoring ratchet mechanismto cont-rol said valve, and a pressure-responsive device connectedtosaid high pressure connection for actuating said ratchet mechanism.

5. A structure as set forth in claim 4 wherein said reversing valve isself-restoring upon self-restoration of said ratchet mechanism, wherebythe engine-piston is movable from normal position by only a singleimpulse.

6. In a stoker ram driving system, the combination with a ram, of itsengine, a source of hydraulic pressuresupply, high pressure and returnconnections therefor, a valve for opening direct connection between saidhigh pressure and return connections, impulse-responsive and valvingmeans communicating with said connections beyond the first said Valve,arranged normally to. open the pressure and return connectionsrespectively to opposite ends of the engine cylinder and responsive topressure impulses periodically to reverse said connections, said meansinquency in the branch pressure pipes, and, in

association with each engine, impulse-responsive and valving meansnormally opening said pressure and return branches respectively toopposite ends ot the engine cyl# inder and responsive to pressureimpulses in the pressure branch periodically to reverse saidconnections.

8. In a Stoker ram driving system, the combination with a stoker ram, ofits engine, a high pressure pipe, a return pipe, automatic means forperiodically engendering pressure impulses in said high pressure pipe,and valve mechanism normally establishing connections between said highpressure pipe and one end of the engine and between said return pipe andthe other end of the engine and automatically operatable to reversethese connections comprisino' an unbalanced, twopiston valve movabletijiya pressure impulse to effect such reversal andy means operated bypartial movements of the valve for restraining said valve against fullmovement to reversing position during a predetermined number of impulsesand then freeing said valve for full-movement.

CURTIS L. HOWSE.

